Pressure- and electroosmotically-driven flow in capillaries packed with nonporous particles for high-Speed separations
✍ Scribed by Steven R. Witowski; Robert T. Kennedy
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 96 KB
- Volume
- 11
- Category
- Article
- ISSN
- 1040-7685
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✦ Synopsis
The chromatographic performance of capillaries with 20 and 50 m Ž . inner diameter i.d. packed with 4.5 and 3.0 m nonporous particles was evaluated under conditions of pressure-and electroosmotically-driven flow for unretained analytes with the goal of determining column configurations suitable for fast separations with both types of flow. Decreasing column diameter to particle Ž . diameter ratio enhanced performance for pressure-driven flow but not for electroosmotically-driven flow. The improved performance with decreasing seen for pressure-driven flow was attributed to a decrease in the A term of the Knox equation. It was concluded that decreasing in pressure-driven columns enhances the uniformity of the column, allowing for improved performance; however, the use of electroosmotic flow masks heterogeneous flow and thus no benefit in performance is seen from reducing . The best performance was with a 20 m i.d. column packed with 3.0 m particles. This column generated h of 0.30 and min Ž 3,310 platesrs at the highest electroosmotic flow rate tested reduced velocity of . 41 whereas with pressure-driven flow the same column had h of 0.96 and 1,200 min Ž . platesrs at the maximum flow velocity tested reduced velocity of 29 .